Multiple Schedulers and Practice Test

ㅁ Deploy Additional Scheduler

wget https://storage.googleapis.com/kubernetes-release/release/v1.12.0/bin/linux/amd64/kube-scheduler

kube-scheduler.service

ExecStart=/usr/local/bin/kube-scheduler \\
  --config=/etc/kubernetes/config/kube-scheduler.yaml \\
  --scheduler-name=default-scheduler

my-custom-scheduler.service

ExecStart=/usr/local/bin/kube-scheduler \\
  --config=/etc/kubernetes/config/kube-scheduler.yaml \\
  --scheduler-name=my-custom-scheduler

 

ㅁ Deploy Additional Scheduler - kubeadm

/etc/kubernetes/manifests/kube-scheduler.yaml

apiVersion: v1
kind: Pod
metadata:
  name: kube-scheduler
  namespace: kube-system
spec:
  containers:
  - command:
    - kube-scheduler
    - --address=127.0.0.1
    - --kubeconfig=/etc/kubernetes/scheduler.conf
    - --leader-elect=true
    image: k8s.gcr.io./kube-scheduler-amd64:v1.11.3
    name: kube-scheduler

my-custom-scheduler.yaml

apiVersion: v1
kind: Pod
metadata:
  name: my-custom-scheduler
  namespace: kube-system
spec:
  containers:
  - command:
    - kube-scheduler
    - --address=127.0.0.1
    - --kubeconfig=/etc/kubernetes/scheduler.conf
    - --leader-elect=true
    - --scheduler-name=my-custom-scheduler
    - --lock-object-name=my-custom-scheduler
    
    image: k8s.gcr.io/kube-scheduler-amd64:v1.11.3
    name: kube-scheduler
  

View Schedulers

 

새로 생성된 스케줄러(my-custom-scheduler)로 새로운 Pod를 생성하려면

spec.schedulerName: <mu-custom-scheduler>를 지정해 줘야 한다.

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  conatiners:
  - image: nginx
    name: nginx
  schedulerName: my-custom-scheduler

로 정의하여 생성한다.

 

kubectl get events

kubectl logs my-custom-scheduler --name-space=kube-system

 

[Practice Test]

 

ㅁ What is the name of the POD that deploys the default kubernetes scheduler in this environment?

kubectl get pods --namespace=kube-system

 

ㅁ What is the image used to deploy the kubernetes scheduler?

kubectl describe pod kube-scheduler-controlplane --namespace=kube-system | grep -i Image

 

ㅁ Deploy an additional scheduler to the cluster following the given specification.

- Namespace: kube-system

- Name: my-scheduler

- Status: Running

- Custom Scheduler Name

 

cd /etc/kubernetest/manifests/
ls
cp kube-scheduler.yaml /root/my-scheduler.yaml
cd
pwd

my-scheduler.yaml

apiVersion: v1
kind: Pod
metadata:
  annotations:
    scheduler.alpha.kubernetes.io/critical-pod: ""
  creationTimestamp: null
  labels:
    component: my-scheduler
    tier: control-plane
  name: my-scheduler
  namespace: kube-system
spec:
  containers:
  - command:
    - kube-scheduler
    - --address=127.0.0.1
    - --kubeconfig=/etc/kubernetes/scheduler.conf
    - --leader-elect=false
    - --port=10282
    - --scheduler-name=my-scheduler
    - --secure-port=0
    image: k8s.gcr.io/kube-scheduler-amd64:v1.16.0
    imagePullPolicy: IfNotPresent
    livenessProbe:
      failureThreshold: 8
      httpGet:
        host: 127.0.0.1
        path: /healthz
        port: 10282
        scheme: HTTP
      initialDelaySeconds: 15
      timeoutSeconds: 15
    name: kube-scheduler
    resources:
      requests:
        cpu: 100m
    volumeMounts:
    - mountPath: /etc/kubernetes/scheduler.conf
      name: kubeconfig
      readOnly: true
  hostNetwork: true
  priorityClassName: system-cluster-critical
  volumes:
  - hostPath:
      path: /etc/kubernetes/scheduler.conf
      type: FileOrCreate
    name: kubeconfig
status: {}

kubectl create -f my-scheduler.yaml

 

ㅁ A POD definition file is given. use it to create a POD with the new custom scheduler.

- name: nginx

- Users custom scheduler

- Status: Running

 

/root/nginx-pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  schedulerName: my-scheduler
  containers:
  - image: nginx
    name: nginx

kubectl create -f nginx-pod.yaml

watch "kubectl get pods"

kubectl describe pod nginx